cache generated host-meta xml

app/controllers/diaspora_federation/webfinger_controller.rb

@@ -15,8 +15,7 @@ module DiasporaFederation
     #
     # GET /.well-known/host-meta
     def host_meta
-      doc = WebFinger::HostMeta.from_base_url(DiasporaFederation.server_uri.to_s)
+      render body: WebfingerController.host_meta_xml, content_type: "application/xrd+xml"
-      render body: doc.to_xml, content_type: "application/xrd+xml"
     end
 
     ##
@@ -34,6 +33,13 @@ module DiasporaFederation
 
     private
 
+    ##
+    # creates the host-meta xml with the configured server_uri and caches it
+    # @return [String] XML string
+    def self.host_meta_xml
+      @host_meta_xml ||= WebFinger::HostMeta.from_base_url(DiasporaFederation.server_uri.to_s).to_xml
+    end
+
     def find_person(query)
       DiasporaFederation.person_class.find_local_by_diaspora_handle(query.strip.downcase.gsub("acct:", ""))
     end

lib/diaspora_federation.rb

@@ -1,7 +1,7 @@
 require "diaspora_federation/engine"
 require "diaspora_federation/logging"
 
-require "diaspora_federation/webfinger"
+require "diaspora_federation/web_finger"
 
 ##
 # diaspora* federation rails engine

spec/controllers/diaspora_federation/webfinger_controller_spec.rb

@@ -5,6 +5,7 @@ module DiasporaFederation
     describe "#host_meta" do
       before do
         DiasporaFederation.server_uri = URI("http://localhost:3000/")
+        WebfingerController.instance_variable_set(:@host_meta_xml, nil) # clear cache
       end
 
       it "succeeds" do
@@ -26,6 +27,12 @@ module DiasporaFederation
         expect(WebFinger::HostMeta).to receive(:from_base_url).with("http://localhost:3000/").and_call_original
         get :host_meta
       end
+
+      it "caches the xml" do
+        expect(WebFinger::HostMeta).to receive(:from_base_url).exactly(1).times.and_call_original
+        get :host_meta
+        get :host_meta
+      end
     end
 
     describe "#legacy_webfinger" do